Larramendy M L, Reigosa M A
Environ Mutagen. 1986;8(4):543-54. doi: 10.1002/em.2860080406.
Sister chromatid exchange (SCE) induction by ultraviolet (UV) light was studied in both human and pig whole blood cultures (WBC) and plasma leukocyte cultures (PLC). No variation in SCE frequency was observed between pig WBC and PLC in control as well as in treated cells. Conversely, SCE frequencies of human PLC were consistently higher than those of WBC in control and UV-exposed cells. Thus, red blood cells (RBCs) do not influence the sensitivity of lymphocytes to UV light exposure, and there must be some different culture condition(s) in the induction of SCEs between human WBC and PLC but not in swine lymphocyte cultures. Since the BrdUrd/lymphocyte ratio of WBC was halved in PLC, the effect of BrdUrd concentration in inducing the SCE baseline frequency of PLC may be ruled out. Also, Ficoll-Hypaque-separated human mononuclear leukocytes in culture (MLC), but not pig MLC, showed a two-fold increase in SCE frequency over WBC values. Thus, neither the cell separation technique nor polymorphonuclear leukocytes had a significant role in the elevated SCE frequency of human PLC or MLC. Experiments where human RBCs were titrated into human PLC showed that the induction of an elevated SCE frequency of PLC was suppressed in a dose-dependent manner by the presence of RBCs in the culture medium. Since the incorporation of pig or human RBCs into human PLC as well as into MLC reduced the SCE frequency to that of WBC, a common component and/or function existing in these cells is suggested. Analysis of different RBC components showed that RBCs, specifically RBC ghosts, release a diffusible but not dialyzable "corrective" factor into culture medium that is able to reduce the SCE frequencies of PLC. Antioxidant enzymes such as catalase and horseradish peroxidase were unable to reduce the SCE frequency of human PLC to WBC values.
在人类和猪的全血培养物（WBC）以及血浆白细胞培养物（PLC）中研究了紫外线（UV）诱导的姐妹染色单体交换（SCE）。在对照以及处理过的细胞中，未观察到猪WBC和PLC之间SCE频率的差异。相反，在对照和紫外线照射的细胞中，人类PLC的SCE频率始终高于WBC。因此，红细胞（RBC）不影响淋巴细胞对紫外线照射的敏感性，并且在人类WBC和PLC之间诱导SCE时一定存在一些不同的培养条件，而在猪淋巴细胞培养中则不存在。由于PLC中WBC的BrdUrd/淋巴细胞比率减半，因此可以排除BrdUrd浓度在诱导PLC的SCE基线频率中的作用。此外，培养中的Ficoll-Hypaque分离的人类单核白细胞（MLC），而不是猪MLC，其SCE频率比WBC值增加了两倍。因此，细胞分离技术和多形核白细胞在人类PLC或MLC升高的SCE频率中均未起重要作用。将人类RBC滴定到人类PLC中的实验表明，培养基中RBC的存在以剂量依赖性方式抑制了PLC升高的SCE频率的诱导。由于将猪或人类RBC掺入人类PLC以及MLC中会将SCE频率降低到WBC的频率，因此表明这些细胞中存在共同的成分和/或功能。对不同RBC成分的分析表明，RBC，特别是RBC空壳，向培养基中释放一种可扩散但不可透析的“校正”因子，该因子能够降低PLC的SCE频率。过氧化氢酶和辣根过氧化物酶等抗氧化酶无法将人类PLC的SCE频率降低到WBC值。
